Reception device, reception method, transmission device, and transmission method

ABSTRACT

To enable subtitles (graphics) to be favorably superimposed and displayed on video. 
     A container in a predetermined format is received, the container including a video stream having video data and a subtitle stream having subtitle data. The video stream is decoded to acquire the video data. The subtitle stream is decoded to acquire bitmap data of subtitles. Processing of correcting at least one of a size of the subtitles and a display position of the subtitles, is performed to the bitmap data of the subtitles. The bitmap data of the subtitles to which the processing has been performed, is superimposed on the video data to acquire display video data.

TECHNICAL FIELD

The present technology relates to a reception device, a receptionmethod, a transmission device, and a transmission method, and moreparticularly relates to, for example, a reception device thatsuperimposes and displays subtitles and graphics on video.

BACKGROUND ART

Conventionally, for example, management of transmitting subtitle data inbitmap data has been performed in broadcasting, such as digital videobroadcasting (DVB). Recently, transmitting information on subtitles, ina character code of text, namely, on a text basis, has been proposed(refer to Patent Document 1).

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2012-169885

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

A conventional method of transmitting subtitles (captions) is on thepremise that data is sent having precision dependent on the resolutionof video being a background, and thus a display is performed inaccordance with the premise. It is desired that the position and size ofthe subtitles superimposed and displayed on the video, can be correctedon the basis of the size of a monitor screen or the viewing position ofa viewer, on the reception side.

An object of the present technology is to enable subtitles (graphics) tobe superimposed and displayed on video.

Solutions to Problems

According to a concept of the present technology, a reception deviceincludes: a reception unit configured to receive a container in apredetermined format, the container including a video stream havingvideo data and a subtitle stream having subtitle data; and a controlunit configured to control video decode processing of decoding the videostream to acquire the video data, subtitle decode processing of decodingthe subtitle stream to acquire bitmap data of subtitles, subtitleprocessing of performing processing of correcting at least one of a sizeof the subtitles and a display position of the subtitles to the bitmapdata of the subtitles, and video superimposition processing ofsuperimposing the bitmap data of the subtitles to which the processinghas been performed, on the video data.

According to the present technology, the reception unit receives thecontainer in the predetermined format, the container including the videostream having the video data and the subtitle stream having the subtitledata. The control unit controls the video decode processing, thesubtitle decode processing, the subtitle processing, and the videosuperimposition processing. The video stream is decoded to acquire thevideo data, in the video decode processing. The subtitle stream isdecoded to acquire the bitmap data of the subtitles, in the subtitledecode processing.

The processing of correcting the at least one of the size of thesubtitles and the display position of the subtitles is performed to thebitmap data of the subtitles, in the subtitle processing. In addition,the bitmap data of the subtitles to which the processing has beenperformed, is superimposed on the video data, in the videosuperimposition processing.

According to the present technology in this manner, the processing ofcorrecting the at least one of the size of the subtitles and the displayposition of the subtitles, can be performed to the bitmap data of thesubtitles so that the subtitles can be favorably superimposed anddisplayed on the video.

Note that, according to the present technology, for example, the atleast one of the size of the subtitles and the display position of thesubtitles may be automatically corrected on the basis of viewingposition information and monitor size information, in the subtitleprocessing. The automatic correction is performed in this manner so thatthe size or display position of the subtitles can be brought into anappropriate state with a user, such as a viewer, not required to performa time-consuming operation.

In this case, for example, an information acquisition unit that acquiresthe viewing position information, may be further provided. In addition,in this case, for example, in the subtitle processing, the followingexpression may be calculated: R=D/(M_h*f), the D representing a viewingdistance, the M_h representing a height of a monitor, the f representinga value dependent on resolution of a video, to perform scale-downcorrection to the size of the subtitles when the R is smaller than afirst threshold value, and to perform scale-up correction to the size ofthe subtitles when the R is larger than a second threshold value largerthan the first threshold value.

In addition, in this case, for example, in the subtitle processing, whena viewing horizontal position is present outer than an end point of aregion in a horizontal direction, the region being an area on which thesubtitles are displayed, a position of the region may be moved to theviewing horizontal position in the horizontal direction in accordancewith a distance from the end point to the viewing horizontal position,to automatically correct the display position of the subtitles. Inaddition, in this case, for example, in the subtitle processing, when aviewing vertical position is present outer than an end point of theregion in a vertical direction, the region being the area on which thesubtitles are displayed, the position of the region may be moved to theviewing vertical position in the vertical direction in accordance with adistance from the end point to the viewing vertical position, toautomatically correct the display position of the subtitles.

In addition, according to the present technology, for example, the atleast one of the size of the subtitles and the display position of thesubtitles may be corrected on the basis of a user operation, in thesubtitle processing. In this case, the user, such as the viewer, canbring the size or display position of the subtitles into a desiredstate.

In addition, according to the present technology, for example, thecorrection of the at least one of the size and display position of thesubtitles may be limited within an allowable range, in the subtitleprocessing. The correction is limited within the allowable range in thismanner so that excessive correction can be avoided being performed.

In this case, for example, an information extraction unit that extractsallowable range information on the correction from a layer of thesubtitle stream, may be further provided, the allowable rangeinformation on the correction being inserted into the layer of thesubtitle stream. In the subtitle processing, the correction may belimited within the allowable range on the basis of the allowable rangeinformation that has been extracted. In this case, the allowable rangeinformation inserted into the layer of the subtitle stream is used sothat the limitation of the size correction or the display positioncorrection of the subtitles can be appropriately performed.

In addition, according to a different concept of the present technology,a transmission device includes: a transmission unit configured totransmit a container in a predetermined format, the container includinga video stream having video data and a subtitle stream having subtitledata; and an information insertion unit configured to insert at leastone of a piece of information indicating an allowable range of sizecorrection of subtitles and a piece of information indicating anallowable range of display position correction of the subtitles, into alayer of the subtitle stream.

According to the present technology, the transmission unit transmits thecontainer in the predetermined format, the container including the videostream having the video data and the subtitle stream having the subtitledata. The information insertion unit inserts the at least one of thepiece of information indicating the allowable range of the sizecorrection of the subtitles and the piece of information indicating theallowable range of the display position correction of the subtitles,into the layer of the subtitle stream.

According to the present technology in this manner, the correctionallowable range information on the size or display position of thesubtitles, is inserted into the layer of the subtitle stream. Therefore,the size correction or the display position correction of the subtitlescan be appropriately limited with the correction allowable rangeinformation, on the reception side.

In addition, according to a different concept of the present technology,a reception device includes: a reception unit configured to receive acontainer in a predetermined format, the container including a videostream having video data and a graphics stream having graphics data; anda control unit configured to control video decode processing of decodingthe video stream to acquire the video data, graphics decode processingof decoding the graphics stream to acquire bitmap data of graphics,graphics processing of performing processing of correcting at least oneof a size of the graphics and a display position of the graphics to thebitmap data of the graphics, and video superimposition processing ofsuperimposing the bitmap data of the graphics to which the processinghas been performed, on the video data.

In addition, according to a different concept of the present technology,a transmission device includes: a transmission unit configured totransmit a container in a predetermined format, the container includinga video stream having video data and a graphics stream having graphicsdata; and an information insertion unit configured to insert at leastone of a piece of information indicating an allowable range of sizecorrection of graphics and a piece of information indicating anallowable range of display position correction of the graphics, into alayer of the graphics stream.

Effects of the Invention

According to the present technology, the subtitles can be favorablysuperimposed and displayed on the video. Note that the effects describedin the present specification are, but are not limited to, justexemplifications, and thus additional effects may be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of an exemplary configuration of atransmission and reception system according to an embodiment.

FIG. 2 is a block diagram of an exemplary configuration of atransmission device.

FIG. 3 is a table of a TTML structure.

FIG. 4 illustrates exemplary structures of the respective elements ofmetadata (metadata), styling (styling), and layout (layout) present in aheader (head) of the TTML structure.

FIG. 5 is a diagram for describing the start position and end positionof a region.

FIG. 6 is a table of an exemplary structure of body (body) in the TTMLstructure.

FIG. 7 is a table of an exemplary structure of a page compositionsegment.

FIG. 8 is a table of an exemplary structure of a region compositionsegment.

FIG. 9 is a table of an exemplary structure of a CLUT definitionsegment.

FIG. 10 illustrates a table of an exemplary structure of a regionscaling segment into which information indicating allowable ranges ofsize correction and display position correction of subtitles has beeninserted and a table of the descriptions of main information in theexemplary structure.

FIG. 11 is a table of an exemplary structure of the styling (TTS) intowhich the information indicating the allowable ranges of the sizecorrection and the display position correction of the subtitles has beeninserted.

FIG. 12 is a diagram for describing automatic correction of the positionof the region (the display position of the subtitles) on the receptionside.

FIG. 13 is a diagram of a viewing distance D and a height of a monitorM_h.

FIG. 14 is a diagram for describing the automatic correction of theposition of the region (the display position of the subtitles) on thereception side.

FIG. 15 is a diagram of an exemplary configuration of a transport streamTS.

FIG. 16 is a block diagram of an exemplary configuration of a receptiondevice.

FIG. 17 illustrates diagrams each for describing a configuration ofacquiring viewing position information.

FIG. 18 illustrates diagrams for describing corrections of the size anddisplay position of the subtitles.

FIG. 19 is a flowchart of exemplary automatic correction processing ofthe size of the subtitles in a size/position conversion unit.

FIG. 20 is a flowchart of exemplary correction processing of the size ofthe subtitles in the size/position conversion unit based on a useroperation.

FIG. 21 is a flowchart of exemplary automatic correction processing ofthe display position of the subtitles in the size/position conversionunit.

FIG. 22 is a flowchart of exemplary correction processing of the displayposition of the subtitles in the size/position conversion unit based onthe user operation.

MODE FOR CARRYING OUT THE INVENTION

A mode for carrying out the invention (hereinafter, referred to as an“embodiment”) will be described below. Note that the descriptions willbe given in the following order.

1. Embodiment

2. Modification

1. Embodiment

[Exemplary Configuration of Transmission and Reception System]

FIG. 1 illustrates an exemplary configuration of a transmission andreception system 10 according to the embodiment. The transmission andreception system 10 includes a transmission device 100 and a receptiondevice 200.

The transmission device 100 generates a transport stream TS of MPEG2 asa container and disposes the transport stream TS onto a packet of abroadcast wave or a net so as to transmit the transport stream TS. Thetransport stream TS includes a video stream having video data (imagedata).

In addition, the transport stream TS includes a subtitle stream havingsubtitle data (caption data). Here, the subtitle data includes textinformation on subtitles in a predetermined format or bitmap data of thesubtitles. Information indicating allowable ranges of size correctionand display position correction of the subtitles, is inserted into alayer of the subtitle stream.

The reception device 200 receives the transport stream TS transmittedfrom the transmission device 100. The reception device 200 performsdecode processing to the video stream so as to acquire the video data,and additionally performs decode processing to the subtitle stream so asto acquire the bitmap data of the subtitles.

The reception device 200 performs processing of correcting the size anddisplay position of the subtitles, to the bitmap data of the subtitles.Then, the reception device 200 superimposes the bitmap data of thesubtitles to which the processing of the size correction and the displayposition correction has been performed, on the video data so as toacquire display video data.

The reception device 200 automatically performs the correctionprocessing on the basis of viewing position information and monitor sizeinformation. In addition, the reception device 200 performs thecorrection processing on the basis of a user operation of, for example,a viewer. The reception device 200 limits the corrections of the sizeand display position of the subtitles, within the allowable ranges.

The reception device 200 extracts the information indicating theallowable ranges of the size correction and the display positioncorrection of the subtitles from the layer of the subtitle stream anduses the information in performing the limitations. When the correctionallowable range information cannot be extracted from the layer of thesubtitle stream, the reception device 200 uses information set as adefault.

[Exemplary Configuration of Transmission Device]

FIG. 2 illustrates an exemplary configuration of the transmission device100. The transmission device 100 includes a control unit 101, a camera102, a video optic-electric conversion unit 103, an RGB/YCbCr conversionunit 104, a video encoder 105, a subtitle generation unit 106, a textformat conversion unit 107, a subtitle encoder 108, a system encoder109, and a transmission unit 110.

Note that, in a case where transmitting, as the subtitle data, thebitmap data of the subtitles instead of transmitting, as the subtitledata, the text information on the subtitles, the transmission device 100includes a bitmap data generation unit 111 and a subtitle encoder 113instead of including the text format conversion unit 107 and thesubtitle encoder 108.

The control unit 101 includes a central processing unit (CPU), andcontrols the operation of each unit of the transmission device 100 onthe basis of control programs. The camera 102 captures a subject so asto output the video data (the image data). The video optic-electricconversion unit 103 performs optic-electric conversion to the video dataacquired by the camera 102 so as to acquire transmission video data V1.

The RGB/YCbCr conversion unit 104 converts the transmission video datafrom an RGB domain into an YCbCr (luminance/chrominance) domain. Forexample, the video encoder 105 performs encoding, such as MPEG4-AVC orHEVC, to the transmission video data V1 converted into the YCbCr domain,so as to generate the video stream (a PES stream) VS including encodedvideo data.

The subtitle generation unit 106 generates text data (a character code)DT as subtitle information. The text format conversion unit 107 receivesthe text data DT so as to acquire the text information on the subtitlesin the predetermined format, namely, timed text markup language (TTML)in the present embodiment.

FIG. 3 illustrates an exemplary timed text markup language (TTML)structure. The TTML is described on an XML basis. In the illustratedexample, a subtitle display current area is specified with “tts:extent”at the position of a root container (root container). For example, therespective elements of metadata (metadata), styling (styling), andlayout (layout) are present in a header (head). FIG. 4(a) illustrates anexemplary structure of the metadata (TTM: TTML Metadata). The metadataincludes information on a title of the metadata and information on acopyright.

FIG. 4(b) illustrates an exemplary structure of the styling (TTS: TTMLStyling). The styling includes information, such as the position andsize of a region (Region), a color (color), a font (fontFamily), a fontsize (fontSize), and a text alignment (textAlign), in addition to anidentifier (id).

“tts:origin” specifies, with pixel counts, the start position of theregion (Region) being a display area of the subtitles. “tts:origin‘480px600px’” is set in the example, and, as illustrated in FIG. 5, the startposition is indicated with (480, 600). In addition, “tts:extent”specifies, with offset pixel counts from the start position in ahorizontal direction and in a vertical direction, the end position ofthe region. “tts:extent‘560px 350px’” is set in the example, and the endposition is indicated with (480+560, 600+350). Here, the offset pixelcounts correspond to the horizontal and vertical sizes of the region.

“tts:opacity=‘1.0’” indicates the mixing ratio of the subtitles(captions) and background video. For example, “1.0” indicates that thesubtitles account for 100% and the background video accounts for 0%, and“0.1” indicates that the subtitles (the captions) account for 0% and thebackground video accounts for 100%. “1.0” is set in the illustratedexample.

FIG. 4(c) illustrates an exemplary structure of the layout (TTMLlayout). The layout includes information, such as an offset (padding), abackground color (backgroundColor), and an alignment (displayAlign), inaddition to the identifier (id) of the region in which the subtitles arearranged. Note that information on the position and size of the region(Region) may be included in the layout.

FIG. 6 illustrates an exemplary structure of body (body). Information onthree subtitles including a subtitle 1 (subtitle 1), a subtitle 2(subtitle 2), and a subtitle 3 (subtitle 3), is included in theillustrated example. Per subtitle, display start timing and display endtiming are described and additionally text data is described. Forexample, for the subtitle 1 (subtitle 1), the display start timing isset to “0.76 s”, the display end timing is set to “3.45 s”, and the textdata is set to “It seems a paradox, dose it not,”.

Referring back to FIG. 2, the subtitle encoder 108 converts the TTMLacquired by the text format conversion unit 107, into various segments,and generates the subtitle stream SS including a PES packet includingthe segments arranged in a payload.

In addition, the bitmap data generation unit 111 receives the text dataDT generated by the subtitle generation unit 106 so as to generate thebitmap data of the subtitles. The subtitle encoder 113 converts thebitmap data of the subtitles and display control information intovarious segments, and generates the subtitle stream SS including a PESpacket including the segments arranged in a payload.

In this case, a page composition segment (page_composition_segment)includes information on the start position of the region (Region) beingthe display area of the subtitles. FIG. 7 illustrates an exemplarystructure (Syntax) of the page composition segment that has beenconventionally known. The field of “region_horizontal_address” and thefield of “region_vertical_address” indicate the start position of theregion (Region).

In addition, in this case, a region composition segment(region_composition_segment) includes information indicating thehorizontal and vertical sizes of the region. FIG. 8 illustrates anexemplary structure (Syntax) of the region composition segment that hasbeen conventionally known. The field of “region_width” and the field of“region_height” indicate the horizontal and vertical sizes of theregion.

In addition, in this case, a CLUT definition segment(CLUT_definition_segment) includes information indicating the mixingratio of the subtitles (the captions) and the background video. FIG. 9illustrates an exemplary structure (Syntax) of the CLUT definitionsegment that has been conventionally known. The field of “T-value”indicates the mixing ratio of the subtitles and the background video.

Referring back to FIG. 2, the system encoder 109 generates the transportstream TS including the video stream VS generated by the video encoder105 and the subtitle stream SS generated by the subtitle encoder 108 orthe subtitle encoder 113. The transmission unit 110 disposes thetransport stream TS onto the packet of the broadcast wave or the net soas to transmit the transport stream TS to the reception device 200.

Here, the transmission device 100 inserts, as described above, theinformation indicating the allowable ranges of the size correction andthe display position correction of the subtitles, into the layer of thesubtitle stream SS. In a case where the bitmap data of the subtitles istransmitted as the subtitle data, namely, in a case where the transportstream TS includes the subtitle stream SS generated by the subtitleencoder 113, for example, a segment including the information indicatingthe allowable ranges of the size correction and the display positioncorrection of the subtitles, is inserted into the subtitle stream SS.

FIG. 10(a) illustrates an exemplary structure (syntax) of a regionscaling segment (Region_scaling_Segment) to be newly defined, and FIG.10(b) illustrates the descriptions (Semantics) of main information inthe exemplary structure. The segment includes information on“sync_byte”, “segment_type”, “page_id”, “segment_length”, “region_id”,“scale_up_factor”, “scale_down_factor”, “positioning_horizontal_factor”,and “positioning_vertical_factor”, present.

The 8-bit field of the “segment_type” indicates a segment type, andrepresents here the region scaling segment. The 8-bit field of the“segment_length” indicates the length (the size) of the segment. The8-bit field of the “region_id” indicates an identifier that identifiesthe region.

The 8-bit field of the “scale_up_factor” indicates the allowable maximumvalue of a region scale-up factor. The 8-bit field of the“scale_down_factor” indicates the allowable minimum value of a regionscale-down factor. The information on the “scale_up_factor” and the“scale_down_factor” is included in the information indicating theallowable range of the size correction of the subtitles.

The 8-bit field of the “positioning_horizontal_factor” indicates theallowable maximum value of a region horizontal positioning factor. The8-bit field of the “positioning_vertical_factor” indicates the allowablemaximum value of a region vertical positioning factor. The informationon the “positioning_horizontal_factor” and the“positioning_vertical_factor” is included in the information indicatingthe allowable range of the display position correction of the subtitles.

In addition, in a case where the text information on the subtitles istransmitted as the subtitle data, namely, in a case where the transportstream TS includes the subtitle stream SS generated by the subtitleencoder 108, for example, the information indicating the allowableranges of the size correction and the display position correction of thesubtitles is inserted with the element of the styling (TTS).

FIG. 11 illustrates an exemplary structure of the styling (TTS) in thatcase. “tts:scale_up_factor” indicates the allowable maximum value of theregion scale-up factor. The illustrated example indicates that theallowable maximum value is “aa %”. “tts:scale_down_factor” indicates theallowable minimum value of the region s scale-down factor. Theillustrated example indicates that the allowable maximum value is “bb%”.

“tts:positioning_horizontal_factor” indicates the allowable maximumvalue of the region horizontal positioning factor. The illustratedexample indicates that the allowable maximum value is “cc %”.“tts:positioning_vertical_factor” indicates the allowable maximum valueof the region vertical positioning factor. The illustrated exampleindicates that the allowable maximum value is “dd %”.

Note that, with the detailed description omitted, in a case where thetext information on the subtitles is transmitted as the subtitle data,it is considered that the information indicating the allowable ranges ofthe size correction and the display position correction of the subtitlesis inserted with the element of the layout instead of using the elementof the styling (TTS) as described above.

Automatic correction of the position of the region on the receptionside, namely, of the display position of the subtitles, will bedescribed here. Here, the automatic correction in the horizontaldirection will be described. FIG. 12 illustrates an exemplary case wherea viewing angle E (a viewing horizontal position) at a viewing positionA is a monitor size M_w or less. Here, the monitor size M_w indicates awidth from an original position O to an end portion on the left side ofa monitor in the horizontal direction, the original position O being thecenter of the original display position of the region in the horizontaldirection.

With, as a reference point P, an end portion of the original displayposition of the region on the viewing position side in the horizontaldirection, the following expression is calculated: Q=(E−P)/2. When aviewing distance D is an appropriate viewing distance (=3*M_h) or more,the region is not moved and the reference point P of the displayposition remains. Meanwhile, when the viewing distance D is less thanthe appropriate viewing distance, the region is moved in accordance withthe viewing distance D so that the reference point P of the displayposition is positioned between the Q and the E. In this case, as theviewing distance D decreases, the E is more approached. Note that theM_h is the height of the monitor as illustrated in FIG. 13.

The example illustrated in FIG. 12 illustrates a case where the positionof the viewing position A in the horizontal direction is on the leftside of the original position O. With the detailed description omitted,the position of the region is automatically corrected similarly even ina case where the position of the viewing position A in the horizontaldirection is on the right side of the original position O.

In addition, FIG. 14 illustrates an exemplary case where the viewingangle E (the viewing horizontal position) at a viewing position B islarger than the monitor size M_w. Here, the monitor size M_w illustratesa width from the original position O to an end portion on the right sideof the monitor in the horizontal direction, the original position Obeing the center of the original display position of the region in thehorizontal direction.

With, as the reference point P, an end portion of the original displayposition of the region on the viewing position side in the horizontaldirection, the following expression is calculated: Q=(M_w−P)/2. When theviewing distance D is the appropriate viewing distance (=3*M_h) or more,the region is not moved and the reference point P of the displayposition remains. Meanwhile, when the viewing distance D is less thanthe appropriate viewing distance, the region is moved in accordance withthe viewing distance D so that the reference point P of the displayposition is positioned between the Q and the M_w. In this case, as theviewing distance D decreases, the M_w is more approached.

The example illustrated in FIG. 14 illustrates a case where the positionof the viewing position B in the horizontal direction is on the rightside of the original position O. With the detailed description omitted,the position of the region is automatically corrected similarly even ina case where the position of the viewing position B in the horizontaldirection is on the left side of the original position O.

As illustrated in FIG. 12, in a case where the viewing angle E at theviewing position A is smaller than the monitor size M_w, a horizontalpositioning factor indicating the reference point P is 0%, a horizontalpositioning factor indicating the position Q is 50%, and a horizontalpositioning factor indicating the position E is 100%. In addition, asillustrated in FIG. 14, in a case where the viewing angle E at theviewing position B is larger than the monitor size M_w, a horizontalpositioning factor indicating the reference point P is 0%, a horizontalpositioning factor indicating the position Q is 50%, and a horizontalpositioning factor indicating the position M_w is 100%.

The allowable maximum value of the region horizontal positioning factorindicates, for example, the maximum value allowed by the horizontalpositioning factor defined in this manner. In this case, the allowablemaximum value of the region horizontal positioning factor can have avalue of 0% at a minimum and a value of 100% at a maximum.

Note that, with the detailed description omitted, the automaticcorrection of the position of the region in the vertical direction,namely, of the display position of the subtitles, is performed similarlyto the case in the horizontal direction described above. In addition,the allowable maximum value of the region vertical positioning factorindicates the maximum value allowed by a vertical positioning factordefined similarly to the horizontal positioning factor described above.

Note that it is considered that the region horizontal positioning factoris defined as the positioning amount of the region to the size of themonitor in the horizontal direction. In this case, the allowable maximumvalue of the region horizontal positioning factor indicates the maximumvalue allowed by the horizontal positioning factor defined in thismanner. Similarly, it is considered that the region vertical positioningfactor is defined as the positioning amount of the region to the size ofthe monitor in the vertical direction. In this case, the allowablemaximum value of the region vertical positioning factor indicates themaximum value allowed by the vertical positioning factor defined in thismanner. The allowable maximum value of the region horizontal positioningfactor and the allowable maximum value of the region verticalpositioning factor are not limited by the viewing position.

[Exemplary Configuration of Transport Stream TS]

FIG. 15 illustrates an exemplary configuration of the transport streamTS. A PES packet “Video PES1” of the video stream identified with aPID1, is present in the exemplary configuration. In addition, the PESpacket “Subtitle PES2” of the subtitle stream identified with a PID2, ispresent in the exemplary configuration.

The PES packets each include a PES header (PES header) and a PES payload(PES payload). The PES packet of the video stream includes a video codedstream inserted into the PES payload. In addition, the PES packet of thesubtitle stream includes the information indicating the allowable rangesof the size correction and the display position correction of thesubtitles, inserted into the element of the styling (TTS) present in theheader of the TTML structure or the region scaling segment.

In addition, the transport stream TS includes a program map table (PMT)as program specific information (PSI). The PSI includes informationdescribing to which program each elementary stream included in thetransport stream belongs. The PMT includes a program loop (Program loop)describing information relating to the entire programs, present.

In addition, the PMT includes an elementary stream loop includinginformation relating to each elementary stream, present. The exemplaryconfiguration includes a video elementary stream loop (video ES loop)corresponding to the video stream and a subtitle elementary stream loop(Subtitle ES loop) corresponding to the subtitle stream, present.

The video elementary stream loop (video ES loop) includes information,such as a stream type and a packet identifier (PID), arranged inresponse to the video stream and additionally includes a descriptordescribing information relating to the video stream, arranged. The valueof “Stream_type” of the video stream is set to, for example, a valueindicating an HEVC video stream, and the PID information indicates thePID1 given to the PES packet “video PES1” of the video stream.

The subtitle elementary stream loop (Subtitle ES loop) includesinformation, such as a stream type and a PID (a packet identifier),arranged in response to the subtitle stream and additionally includes adescriptor describing information relating to the subtitle stream,arranged. The value of “Stream_type” of the subtitle stream is set to,for example, a value indicating a private stream, and the PIDinformation indicates the PID2 given to the PES packet “Subtitle PES2”of the subtitle stream.

The operation of the transmission device 100 illustrated in FIG. 2 willbe simply described. The video data (the image data) captured andacquired by the camera 102, is supplied to the video optic-electricconversion unit 103. The video optic-electric conversion unit 103performs the optic-electric conversion to the video data acquired by thecamera 102 so as to acquire the transmission video data V1.

The transmission video data V1 acquired by the video optic-electricconversion unit 103, is converted from the RGB domain into the YCbCr(the luminance/chrominance) domain by the RGB/YCbCr conversion unit 104,so as to be supplied to the video encoder 105. The video encoder 105performs the encoding, such as MPEG4-AVC or HEVC, to the transmissionvideo data V1 so as to generates the video stream (the PES stream) VSincluding the encoded video data.

The subtitle generation unit 106 generates the text data (the charactercode) DT as the subtitle information. In a case where the textinformation of the subtitles is transmitted as the subtitle data, thetext data DT is supplied to the text format conversion unit 107.

The text format conversion unit 107 makes a conversion to the textinformation on the subtitles, including display timing, namely, theTTML, on the basis of the text data DT (refer to FIG. 3). The TTML issupplied to the subtitle encoder 108.

The subtitle encoder 108 converts the TTML acquired by the text formatconversion unit 107, into the various segments, and generates thesubtitle stream SS including the PES packet including the segmentsarranged in the payload.

In addition, in a case where the bitmap data of the subtitles istransmitted as the subtitle data, the text data DT generated by thesubtitle generation unit 106 is supplied to the bitmap data generationunit 111.

The bitmap data generation unit 111 generates the bitmap data of thesubtitles on the basis of the text data DT. The bitmap data of thesubtitles is supplied to the subtitle encoder 113. The subtitle encoder113 converts the transmission bitmap data M1 and the display controlinformation into the various segments, and generates the subtitle streamSS including the PES packet including the segments arranged in thepayload.

The video stream VS generated by the video encoder 105 is supplied tothe system encoder 109. The subtitle stream SS generated by the subtitleencoder 108 or the subtitle encoder 113, is supplied to the systemencoder 109. The system encoder 109 generates the transport stream TSincluding the video stream VS and the subtitle stream SS. Thetransmission unit 110 disposes the transport stream TS onto the packetof the broadcast wave or the net so as to transmit the transport streamTS to the reception device 200.

In addition, the transmission device 100 inserts the informationindicating the allowable ranges of the size correction and the displayposition correction of the subtitles, into the layer of the subtitlestream SS. In a case where the bitmap data of the subtitles istransmitted as the subtitle data, the region scaling segment to be newlydefined, including the information indicating the allowable ranges ofthe size correction and the display position correction of thesubtitles, is inserted into the subtitle stream SS (refer to FIG. 10).In addition, in a case where the text information on the subtitles istransmitted as the subtitle data, for example, the informationindicating the allowable ranges of the size correction and the displayposition correction of the subtitles, is inserted with the element ofthe styling (TTS) (refer to FIG. 11).

[Exemplary Configuration of Reception Device]

FIG. 16 illustrates an exemplary configuration of the reception device200. The reception device 200 includes a control unit 201, a receptionunit 202, a system decoder 203, a video decoder 204, a subtitle decoder206, a font expansion unit 207, an RGB/YCbCr conversion unit 208, and asubtitle decoder 209.

In addition, the reception device 200 includes a size/positionconversion unit 210, a size/position conversion unit 211, a videosuperimposition unit 212, an YCbCr/RGB conversion unit 213, anelectric-optic conversion unit 214, a display mapping unit 215, a CEmonitor 216, a user operation unit 231, and an image sensor 232.

The control unit 201 includes a central processing unit (CPU), andcontrols the operation of each unit of the reception device 200 on thebasis of control programs. The user operation unit 231 includes, forexample, switches, a touch panel, and a remote controller transmissionunit with which a user, such as the viewer, performs various operations.As illustrated in FIG. 17(a), the image sensor 232 is arranged on thefront side of the reception device 200, and acquires an image includingthe viewer in front of the monitor so as to send the image to thecontrol unit 201.

The image sensor 232 together with the control unit 201 is included inan information acquisition unit that acquires the viewing positioninformation. The control unit 201 analyzes the image acquired by theimage sensor 232 and detects the viewer so as to acquire the viewingposition information (the viewing distance D and the viewing angle E).Note that the configuration of acquiring the viewing positioninformation is not limited to a configuration with the image sensor 232in this manner. For example, as illustrated in FIG. 17(b), in a casewhere a smartphone having a position acquisition function of GPS is usedas a remote controller, it is considered that position informationacquired by the position acquisition function of the smartphone is used.

The reception unit 202 receives the transport stream TS transmitted fromthe transmission device 100, the transport stream TS being disposed onthe packet of the broadcast wave or the net. The system decoder 203extracts the video stream VS and the subtitle stream SS from thetransport stream TS.

The video decoder 204 performs decoding processing to the video streamVS extracted by the system decoder 203 so as to output the transmissionvideo data V1. In addition, the video decoder 204 extracts a parameterset and an SEI message inserted into each access unit included in thevideo stream VS so as to send the parameter set and the SEI message tothe control unit 201.

The subtitle decoder 206 operates in a case where the text informationon the subtitles is transmitted as the subtitle data. The subtitledecoder 206 performs decode processing to segment data of each regionincluded in the subtitle stream SS, so as to acquire text data and acontrol code of each region. The control code includes mixing ratioinformation (Mixing data) on the subtitles and the background video,also present.

In addition, the subtitle decoder 206 extracts the informationindicating the allowable ranges of the size correction and the displayposition correction of the subtitles, inserted into the subtitle streamSS, so as to send the information to the control unit 201. In this case,the information has been inserted with the element of the styling (TTS).With this arrangement, the control unit 201 recognizes the allowablemaximum value of the region scale-up factor, the allowable minimum valueof the region scale-down factor, the allowable maximum value of theregion horizontal positioning factor, and the allowable maximum value ofthe region vertical positioning factor.

The font expansion unit 207 performs font expansion on the basis of thetext data and the control code of each region acquired by the subtitledecoder 206, so as to acquire the bitmap data of each region. The bitmapdata of the subtitles is acquired in the RGB domain. The RGB/YCbCrconversion unit 208 converts the bitmap data of the subtitles acquiredby the font expansion unit 207, from the RGB domain into the YCbCr (theluminance/chrominance) domain.

The subtitle decoder 209 operates in a case where the bitmap data of thesubtitles is transmitted as the subtitle data. In this case, the dataincluded in the subtitle stream SS is transmitted to a CLUT. Thesubtitle decoder 209 performs decode processing to the subtitle streamSS so as to acquire the bitmap data of the subtitles and the mixingratio information (Mixing data) on the subtitles and the backgroundvideo.

In addition, the subtitle decoder 209 extracts the informationindicating the allowable ranges of the size correction and the displayposition correction of the subtitles, inserted into the subtitle streamSS, so as to send the information to the control unit 201. In this case,the information has been inserted into the region scaling segment. Withthis arrangement, the control unit 201 recognizes the allowable maximumvalue of the region scale-up factor, the allowable minimum value of theregion scale-down factor, the allowable maximum value of the regionhorizontal positioning factor, and the allowable maximum value of theregion vertical positioning factor.

The size/position conversion unit 210 performs the processing ofcorrecting the size and display position of the subtitles, to the bitmapdata of the subtitles output from the RGB/YCbCr conversion unit 208 orthe subtitle decoder 209.

The size/position conversion unit 210 automatically performs thecorrection processing, on the basis of the viewing position informationand the monitor size information, under the control of the control unit201. In addition, the size/position conversion unit 210 performs thecorrection processing on the basis of the user operation of, forexample, the viewer. In this case, the size/position conversion unit 210further receives correction with the user operation after performing theautomatic correction.

Alternatively, the size/position conversion unit 210 can bring theautomatic correction into a stop state, with the user operation, andreceives only the correction with the user operation in that case. Inaddition, alternatively, the size/position conversion unit 210 can bringthe correction with the user operation, into a rejection state, andperforms only the automatic correction in that case.

The size/position conversion unit 210 limits the corrections of the sizeand display position of the subtitles, within the allowable ranges.Here, the information indicating the allowable ranges, extracted fromthe subtitle stream SS, is basically used. However, when the informationindicating the allowable ranges is not extracted from the subtitlestream SS, the information set as the default is used.

FIG. 18(a) illustrates an exemplary display state of the subtitles (thecaptions) on the screen in a case where the size of the monitor issmall. FIG. 18(b) illustrates an exemplary display state of thesubtitles (the captions) on the screen in a case where the size of themonitor is large. The size correction of the subtitles has not beenperformed in the example. In this case, the size of the subtitlesincreases in proportion to the size of the monitor. Therefore, when thedistance from the viewer to the monitor, namely, the viewing distance isshort, the size of the subtitles is excessively large so that the vieweris annoyed. In addition, in this case, if the front position of theviewer is excessively away from the display position of the subtitles,the viewer has difficulty in viewing the subtitles naturally.

FIG. 18(c) illustrates an exemplary display state of the subtitles onthe screen in a case where the size of the monitor is large. Scale-downcorrection has been performed to the size of the subtitles in theexample, and thus provided is a state where the viewer is not annoyedeven when the viewing distance is short. In addition, in the example,positioning correction has been performed to cause the display positionof the subtitles to come close to the front position of the viewer sothat the viewer has ease in viewing the subtitles naturally.

[Description of Size Correction Processing of Subtitles]

Size correction processing of the subtitles in the size/positionconversion unit 210, will be described. First, automatic correctionprocessing will be described. In a case where the resolution of thevideo on the monitor is HD, the viewing appropriate distance isexpressed by the ratio of the distance to the monitor to the height ofthe monitor, and the value thereof is appropriately “3”. However, it issaid that the value varies in a case where the resolution of the videois UHD. That is, the value is small, namely, the viewing can be made atcloser range.

In a case where being in a mode in which the automatic correction isallowed, in consideration of this, the size/position conversion unit 210performs the automatic correction processing of the size of thesubtitles. The size/position conversion unit 210 first calculates R withMathematical Formula (1) below including D representing the viewingdistance, M_h representing the height of the monitor, and f representinga value dependent on the resolution of the video. Note that the f has alarger value as the resolution of the video increases.

R=D/(M_h*f)  (1)

Next, the size/position conversion unit 210 performs the size correctionof the subtitles (scale-up or scale-down) in accordance with themagnitude of the R to a threshold value. The size correction of thesubtitles corresponds to size correction of the range of the region. Thesize/position conversion unit 210 performs interpolation processing tothe bitmap data of the subtitles so as to perform the size correction ofthe subtitles.

The size/position conversion unit 210 performs scale-down correction tothe size of the subtitles when the R is smaller than a threshold valueTH1, and performs scale-up correction to the size of the subtitles whenthe R is larger than a threshold value TH2 larger than the thresholdvalue TH1. In this case, the size/position conversion unit 210 limitsthe size correction of the subtitles, within the allowable range.

The flowchart of FIG. 19 illustrates exemplary automatic correctionprocessing of the size of the subtitles in the size/position conversionunit 210. Note that, here, related processing in the control unit 201will be also described as the processing of the size/position conversionunit 210.

The size/position conversion unit 210 first starts the processing atstep ST1. Next, the size/position conversion unit 210 acquires, at stepST2, the viewing distance D, the height of the monitor M_h, andinformation on the resolution of the video. Then, the size/positionconversion unit 210 calculates, at step ST3, the R with MathematicalFormula (1) described above.

Next, the size/position conversion unit 210 determines, at step ST4,whether the following expression has been satisfied: R<TH1. Whendetermining that the following expression has not been satisfied: R<TH1,the size/position conversion unit 210 determines, at step ST5, whetherthe following expression is satisfied: R>TH2. When determining that thefollowing expression has not been satisfied: R>TH2, the size/positionconversion unit 210 completes the processing at step ST6. That is, inthis case, the size/position conversion unit 210 makes the size ofsubtitles remain intact without the correction.

When the size/position conversion unit 210 determines, at step ST5, thatthe following expression has been satisfied: R>TH2, the processingproceeds to step ST7. At step ST7, the size/position conversion unit 210scales up the size of the subtitles with a preset factor. Needless tosay, the scale-up factor is limited within the allowable range. Afterthe processing at step ST7, the size/position conversion unit 210completes the processing at step ST6.

In addition, when the size/position conversion unit 210 determines, atstep ST4, that the following expression has been satisfied: R<TH1, theprocessing proceeds to step ST8. At step ST8, the size/positionconversion unit 210 scales down the size of the subtitles with a presetfactor. Needless to say, the scale-down factor is limited within theallowable range. After the processing at step ST8, the size/positionconversion unit 210 completes the processing at step ST6.

Next, the size correction processing of the subtitles in thesize/position conversion unit 210 based on the user operation, will bedescribed. In this case, the user operation unit 231 supplies operationinformation on the scale-up or scale-down of the size of the subtitles,to the control unit 201. The size/position conversion unit 210 performsthe size correction of the subtitles corresponding to the useroperation, on the basis of a command from the control unit 201.

The flowchart of FIG. 20 illustrates exemplary correction processing ofthe size of the subtitles in the size/position conversion unit 210 basedon the user operation. The flowchart corresponds to a unit operation ofthe user, and the processing of the flowchart is repeated in a casewhere the operation is successively performed.

The size/position conversion unit 210 starts the processing at stepST11. Next, the size/position conversion unit 210 determines, at stepST12, determines whether the command from the control unit 201 is ascale-up order or a scale-down order for the size of the subtitles. Whendetermining the scale-up order, the size/position conversion unit 210scales up, at step ST13, the size of the subtitles by a predeterminedfactor when the upper-limited factor has not been reached.

That is, in this case, in a case where the scale-up factor of the sizeof the subtitles has already reached the allowable maximum value by theautomatic correction processing or the correction processing based onthe previous user operation, the size/position conversion unit 210 doesnot perform the scale-up processing at step ST13. Note that, in thiscase, the CE monitor 216 may display, to the user, a notification thatthe scale-up processing is impossible to perform, on the basis of thecontrol of the control unit 201.

After the processing at step ST13, the size/position conversion unit 210completes the processing at step ST14.

In addition, when determining the scale-down order at step ST12, thesize/position conversion unit 210 scales down, at step ST15, the size ofthe subtitles by a predetermined factor when the lower-limited factorhas not been reached.

That is, in this case, in a case where the scale-down factor of the sizeof the subtitles has already reached the allowable minimum value by theautomatic correction processing or the correction processing based onthe previous user operation, the size/position conversion unit 210 doesnot perform the scale-down processing at step ST15. Note that, in thiscase, the CE monitor 216 may display, to the user, a notification thatthe scale-down processing is impossible to perform, on the basis of thecontrol of the control unit 201.

After the processing at step ST15, the size/position conversion unit 210completes the processing at step ST14.

[Description of Display Position Correction Processing of Subtitles]

Display position correction processing of the subtitles in thesize/position conversion unit 210, will be described. First, automaticcorrection processing will be described. In this case, in a case wherebeing in the mode in which the automatic correction is allowed, thesize/position conversion unit 210 automatically performs the displayposition correction of the subtitles, as described with FIGS. 12 and 14.

The flowchart of FIG. 21 illustrates exemplary automatic correctionprocessing of the display position of the subtitles in the size/positionconversion unit 210. Note that, here, related processing in the controlunit 201 will be also described as the processing of the size/positionconversion unit 210.

The size/position conversion unit 210 first starts the processing atstep ST21. Next, the size/position conversion unit 210 acquires, at stepST22, the viewing distance D, the viewing angle E, the height of themonitor M_h, the width of the monitor M_w, and the information on theresolution of the video. Then, the size/position conversion unit 210acquires, at step ST23, as the reference point P, the end portion of theoriginal display position of the region on the viewing position side. Inthis case, the original display position of the region is the displayposition after the size correction processing when the size correctionprocessing of the subtitles is performed.

Next, the size/position conversion unit 210 determines, at step ST24,whether the viewing angle E is the monitor size M_w or less. Whendetermining that the viewing angle E is the monitor size M_w or less,the size/position conversion unit 210 calculates, at step ST25, the Qwith Mathematical Formula (2) below.

Q=(E−P)/2  (2)

Next, the size/position conversion unit 210 determines, at step ST26,whether the viewing distance D is the appropriate viewing distance(=3*M_h) or more. When determining that the viewing distance D is theappropriate viewing distance or more, the size/position conversion unit210 makes, at step ST27, the reference point P of the display positionremain without moving the region. After the processing at step ST27, thesize/position conversion unit 210 completes the processing at step ST28.

In addition, when the size/position conversion unit 210 determines, atstep ST26, that the viewing distance D is less than the appropriateviewing distance, the processing proceeds to step ST29. At step ST29,the size/position conversion unit 210 moves the region in accordancewith the viewing distance D so that the reference point P of the displayposition is positioned between the Q and the E. In this case, as theviewing distance D decreases, the E is more approached. After theprocessing at step ST29, the size/position conversion unit 210 completesthe processing at step ST28.

In addition, when the size/position conversion unit 210 determines, atstep ST24, that the viewing angle E is larger than the monitor size M_w,the processing proceeds to step ST30. At step ST30, the size/positionconversion unit 210 calculates the Q with Mathematical Formula (3)below.

Q=(M_w−P)/2  (3)

Next, the size/position conversion unit 210 determines, at step ST31,whether the viewing distance D is the appropriate viewing distance(=3*M_h) or more. When determining that the viewing distance D is theappropriate viewing distance or more, the size/position conversion unit210 makes, at step ST32, the reference point P of the display positionremain without moving the region. After the processing at step ST32, thesize/position conversion unit 210 completes the processing at step ST28.

In addition, when the size/position conversion unit 210 determines, atstep ST31, that the viewing distance D is less than the appropriateviewing distance, the processing proceeds to step ST33. At step ST33,the size/position conversion unit 210 moves the region in accordancewith the viewing distance D so that the reference point P of the displayposition is positioned between the Q and the M_w in accordance with theviewing distance D. In this case, as the viewing distance D decreases,the M_w is more approached. After the processing at step ST33, thesize/position conversion unit 210 completes the processing at step ST28.

Next, the display position correction processing of the subtitles in thesize/position conversion unit 210 based on the user operation, will bedescribed. In this case, the user operation unit 231 suppliespositioning operation information on the display position of thesubtitles in the horizontal direction or in the vertical direction, tothe control unit 201. Note that the positioning operation informationincludes information on positioning directions, namely, informationindicating the right or left in the horizontal direction and informationindicating the up or down in the vertical direction. The size/positionconversion unit 210 performs the display position correction of thesubtitles corresponding to the user operation on the basis of a commandfrom the control unit 201.

The flowchart of FIG. 22 illustrates exemplary correction processing ofthe display position of the subtitles in the size/position conversionunit 210 based on the user operation. The flowchart corresponds to aunit operation of the user, and the processing of the flowchart isrepeated in a case where the operation is successively performed.

The size/position conversion unit 210 starts the processing at stepST41. Next, the size/position conversion unit 210 determines, at stepST42, whether the command from the control unit 201 is a positioningorder in the horizontal direction (an H direction) or a positioningorder in the vertical direction (a V direction) for the display positionof the subtitles.

When determining the positioning order in the H direction, thesize/position conversion unit 210 moves, at step ST43, the region in aspecified direction (the right or left) in a range in which thepositioning factor does not exceed the allowable maximum value. Thesize/position conversion unit 210 may not perform the positioningprocessing at step ST13. Note that, in this case, the CE monitor 216 maydisplay, to the user, a notification that the positioning processing isimpossible to perform, on the basis of the control of the control unit201.

After the processing at step ST43, the size/position conversion unit 210completes the processing at step ST44.

In addition, when the size/position conversion unit 210 determines, atstep ST42, the positioning order in the V direction, the size/positionconversion unit 210 moves, at step ST45, the region in a specifieddirection (the up or down) in a range in which the positioning factordoes not exceed the allowable maximum value. The size/positionconversion unit 210 may not perform the positioning processing at stepST45. Note that, in this case, the CE monitor 216 may display, to theuser, a notification that the positioning processing is impossible toperform, on the basis of the control of the control unit 201.

After the processing at step ST45, the size/position conversion unit 210completes the processing at step ST44.

Referring back to FIG. 16, the size/position conversion unit 211performs, to the mixing ratio information (Mixing data) output from thesubtitle decoder 209, correction processing similar to the correctionprocessing of the size and display position of the subtitles in thesize/position conversion unit 211.

The video superimposition unit 212 superimposes the bitmap data of thesubtitles to which the size/position conversion unit 210 has performedthe correction processing of the size and the display position, on thetransmission video data V1 acquired by the video decoder 204. In thiscase, the video superimposition unit 212 mixes the bitmap data of thesubtitles in the mixing ratio indicated with the mixing ratioinformation (Mixing data).

In this case, when the text information on the subtitles is transmittedas the subtitle data from the transmission side, the mixing ratioinformation (Mixing data) acquired by the subtitle decoder 206 is used.Meanwhile, when the bitmap data of the subtitles is transmitted as thesubtitle data from the transmission side, the mixing ratio information(Mixing data) to which the size/position conversion unit 211 hasperformed the correction processing of the size and the displayposition, is used.

The YCbCr/RGB conversion unit 213 converts the transmission video dataV1′ on which the bitmap data of the subtitles has been superimposed,from the YCbCr (the luminance/chrominance) domain into the RGB domain.The electric-optic conversion unit 214 applies, to the transmissionvideo data V1′ converted into the RGB domain, an electric-opticconversion characteristic corresponding to an optic-electric conversioncharacteristic applied to the transmission video data V1′, so as toperform electric-optic conversion so that display video data fordisplaying an image is acquired.

The display mapping unit 215 performs, to the display video data,display luminance adjustment corresponding to, for example, the maximumluminance display performance of the CE monitor 216. The CE monitor 216displays the image on the basis of the display video data. The CEmonitor 216 includes, for example, a liquid crystal display (LCD) or anorganic electroluminescence display (organic EL display).

The operation of the reception device 200 illustrated in FIG. 16, willbe simply described. The reception unit 202 receives the transportstream TS transmitted from the transmission device 100, the transportstream TS being disposed on the packet of the broadcast wave or the net.The transport stream TS is supplied to the system decoder 203. Thesystem decoder 203 extracts the video stream VS and the subtitle streamSS from the transport stream TS.

The video stream VS extracted by the system decoder 203 is supplied tothe video decoder 204. The video decoder 204 performs the decodingprocessing to the video stream VS so as to acquire the transmissionvideo data V1. In addition, the video decoder 204 extracts the parameterset and the SEI message inserted into each access unit included in thevideo stream VS so as to send the parameter set and the SEI message tothe control unit 201.

The subtitle stream SS extracted by the system decoder 203 is suppliedto the subtitle decoder 206 in a case where the text information on thesubtitles is transmitted as the subtitle data. The subtitle decoder 206performs the decode processing to the segment data of each regionincluded in the subtitle stream SS, so as to acquire the text data andthe control code of each region. The control code also includes themixing ratio information (Mixing data) on the subtitles and thebackground video.

In addition, the subtitle decoder 206 extracts the informationindicating the allowable ranges of the size correction and the displayposition correction of the subtitles, inserted into the subtitle streamSS, so as to send the information to the control unit 201. In this case,the information has been inserted with the element of the styling (TTS).With this arrangement, the control unit 201 recognizes the allowablemaximum value of the region scale-up factor, the allowable minimum valueof the region scale-down factor, the allowable maximum value of theregion horizontal positioning factor, and the allowable maximum value ofthe region vertical positioning factor.

The text data and the control code of each region acquired by thesubtitle decoder 206 are supplied to the font expansion unit 207. Thefont expansion unit 207 performs the font expansion on the basis of thetext data and the control code of each region, so as to acquire thebitmap data of each region. The RGB/YCbCr conversion unit 208 convertsthe bitmap data of each region acquired by the font expansion unit 207,from the RGB domain into the YCbCr (the luminance/chrominance) domain.

In addition, the subtitle stream SS extracted by the system decoder 203is supplied to the subtitle decoder 209 in a case where the bitmap dataof the subtitles is transmitted as the subtitle data. The subtitledecoder 209 performs the decode processing to the subtitle stream SS soas to acquire the bitmap data of the subtitles and the mixing ratioinformation (Mixing data) on the subtitles and the background video.

The bitmap data of the subtitles output from the RGB/YCbCr conversionunit 208 or the subtitle decoder 209, is supplied to the size/positionconversion unit 210. The size/position conversion unit 210 performs theprocessing of correcting the size and display position of the subtitles,to the bitmap data of the subtitles. In this case, the correctionprocessing is performed automatically or in accordance with the useroperation, under the control of the control unit 201 (refer to FIGS. 19to 22). The correction is performed within the allowable ranges.

The transmission video data V1 acquired by the video decoder 204 issupplied to the video superimposition unit 211. In addition, the bitmapdata of the subtitles to which the size/position conversion unit 210 hasperformed the correction processing of the size and the displayposition, is supplied to the video superimposition unit 211.Furthermore, the mixing ratio information (Mixing data) acquired by thesubtitle decoder 206 or the mixing ratio information (Mixing data) towhich the size/position conversion unit 211 has performed the correctionprocessing of the size and the display position, is supplied to thevideo superimposition unit 211.

The video superimposition unit 212 superimposes, on the transmissionvideo data V1, the bitmap data of the subtitles to which the correctionsof the size and the display position have been performed automaticallyon the basis of information, such as the monitor size and the viewingposition, or in accordance with the user operation. The transmissionvideo data V1′ on which the bitmap data has been superimposed, issupplied to the YCbCr/RGB conversion unit 213.

The YCbCr/RGB conversion unit 213 converts the transmission video dataV1′ from the YCbCr (the luminance/chrominance) domain into the RGBdomain, so as to supply the transmission video data V1′ to theelectric-optic conversion unit 214. The electric-optic conversion unit214 applies, to the transmission video data V1′, the electric-opticconversion characteristic corresponding to the optic-electric conversioncharacteristic applied to the transmission video data V1′, so as toperform the electric-optic conversion so that the display video data isacquired.

The display video data is supplied to the display mapping unit 215. Thedisplay mapping unit 215 performs, to the display video data, thedisplay luminance adjustment corresponding to, for example, the maximumluminance display performance of the CE monitor 216. The display videodata to which the display luminance adjustment has been performed inthis manner, is supplied to the CE monitor 216. The CE monitor 216displays the image on the basis of the display video data.

As described above, the reception device 200 performs the processing ofcorrecting the size and display position of the subtitles, to the bitmapdata of the subtitles, in the transmission and reception system 10illustrated in FIG. 1. Therefore, the subtitles can be favorablysuperimposed and displayed on the video, for example, even when thedisplay is performed on the monitor having a large screen and theviewing distance is short.

In addition, the reception device 200 automatically corrects the size ofthe subtitles and the display position of the subtitles on the basis ofthe viewing position information and the monitor size information, inthe transmission and reception system 10 illustrated in FIG. 1.Therefore, the size and display position of the subtitles can be broughtinto an appropriate state with the user, such as the viewer, notrequired to perform a time-consuming operation.

In addition, the reception device 200 corrects the size of the subtitlesand the display position of the subtitles on the basis of the useroperation, in the transmission and reception system 10 illustrated inFIG. 1. Therefore, the user, such as the viewer, can bring the size anddisplay position of the subtitles into a desired state.

In addition, the reception device 200 limits the corrections of the sizeand display position of the subtitles, within the allowable ranges, inthe transmission and reception system 10 illustrated in FIG. 1.Therefore, excessive corrections can be avoided.

In addition, the reception device 200 extracts the correction allowablerange information from the layer of the subtitle stream so as to limitthe corrections of the size and display position of the subtitles withinthe allowable ranges on the basis of the allowable range information, inthe transmission and reception system 10 illustrated in FIG. 1.Therefore, the size correction and the display position correction ofthe subtitles can be appropriately limited.

In addition, the transmission device 100 inserts the correctionallowable range information on the size and display position of thesubtitles, into the layer of the subtitle stream so as to transmit thecorrection allowable range information, in the transmission andreception system 10 illustrated in FIG. 1. Therefore, the sizecorrection and the display position correction of the subtitles can beappropriately limited with the correction allowable range information,on the reception side.

2. Modification

Note that, according to the embodiment described above, the example inwhich the size and display position of the subtitles can be corrected,has been given. The present technology can be similarly applied to evena case where graphics or other similar information is superimposed anddisplayed on the video, and thus the size and display position of thegraphics or the other similar information can be favorably corrected.

In addition, according to the embodiment described above, the example inwhich the container is MPEG-2 TS, has been given. However, the presenttechnology is not limited to MPEG-2 TS as the container, and thus can besimilarly applied to other packets, such as ISOBMFF and MMT.

In addition, the present technology can have the followingconfigurations.

(1) A reception device includes: a reception unit configured to receivea container in a predetermined format, the container including a videostream having video data and a subtitle stream having subtitle data; avideo decode unit configured to perform decode processing to the videostream to acquire the video data; a subtitle decode unit configured toperform decode processing to the subtitle stream to acquire bitmap dataof subtitles; a subtitle processing unit configured to performprocessing of correcting at least one of a size of the subtitles and adisplay position of the subtitles to the bitmap data of the subtitles;and a video superimposition unit configured to superimpose the bitmapdata of the subtitles to which the processing has been performed, on thevideo data.

(2) According to the reception device described in (1) above, thesubtitle processing unit automatically corrects the at least one of thesize of the subtitles and the display position of the subtitles on thebasis of viewing position information and monitor size information.

(3) The reception device described in (2) above, further includes: aninformation acquisition unit configured to acquire the viewing positioninformation.

(4) According to the reception device described in (2) or (3) above, thesubtitle processing unit calculates the following expression:R=D/(M_h*f), the D representing a viewing distance, the M_h representinga height of a monitor, the f representing a value dependent onresolution of a video, to perform scale-down correction to the size ofthe subtitles when the R is smaller than a first threshold value, and toperform scale-up correction to the size of the subtitles when the R islarger than a second threshold value larger than the first thresholdvalue.

(5) According to the reception device described in any of (2) to (4)above, the subtitle processing unit moves, when a viewing horizontalposition is present outer than an end point of a region in a horizontaldirection, the region being an area on which the subtitles aredisplayed, a position of the region to the viewing horizontal positionin the horizontal direction in accordance with a distance from the endpoint to the viewing horizontal position, to automatically correct thedisplay position of the subtitles.

(6) According to the reception device described in (2) to (4) above, thesubtitle processing unit moves, when a viewing vertical position ispresent outer than an end point of a region in a vertical direction, theregion being an area on which the subtitles are displayed, a position ofthe region to the viewing vertical position in the vertical direction inaccordance with a distance from the end point to the viewing verticalposition, to automatically correct the display position of thesubtitles.

(7) According to the reception device described in any of (1) to (6)above, the subtitle processing unit corrects the at least one of thesize of the subtitles and the display position of the subtitles on thebasis of a user operation.

(8) According to the reception device described in any of (1) to (7)above, the subtitle processing unit limits at least one of thecorrection of the size of the subtitles and the correction of thedisplay position of the subtitles within an allowable range.

(9) The reception device described in (8) above, further includes: aninformation extraction unit configured to extract allowable rangeinformation on the correction from a layer of the subtitle stream, theallowable range information on the correction being inserted into thelayer of the subtitle stream. The subtitle processing unit limits thecorrection within the allowable range on the basis of the allowablerange information on the correction that has been extracted.

(10) A reception method includes: a reception step of receiving acontainer in a predetermined format by a reception unit, the containerincluding a video stream having video data and a subtitle stream havingsubtitle data; a video decode step of performing decode processing tothe video stream to acquire the video data; a subtitle decode step ofperforming decode processing to the subtitle stream to acquire bitmapdata of subtitles; a subtitle processing step of performing processingof correcting at least one of a size of the subtitles and a displayposition of the subtitles, to the bitmap data of the subtitles; and avideo superimposition step of superimposing the bitmap data of thesubtitles to which the processing has been performed, on the video data.

(11) A transmission device includes: a transmission unit configured totransmit a container in a predetermined format, the container includinga video stream having video data and a subtitle stream having subtitledata; and an information insertion unit configured to insert at leastone of a piece of information indicating an allowable range of sizecorrection of subtitles and a piece of information indicating anallowable range of display position correction of the subtitles, into alayer of the subtitle stream.

(12) A transmission method includes: a transmission step of transmittinga container in a predetermined format by a transmission unit, thecontainer including a video stream having video data and a subtitlestream having subtitle data; and an information insertion step ofinserting at least one of a piece of information indicating an allowablerange of size correction of the subtitles and a piece of informationindicating an allowable range of display position correction of thesubtitles, into a layer of the subtitle stream.

(12) A reception device includes: a reception unit configured to receivea container in a predetermined format, the container including a videostream having video data and a graphics stream having graphics data; avideo decode unit configured to perform decode processing to the videostream to acquire the video data; a graphics decode unit configured toperform decode processing to the graphics stream to acquire bitmap dataof graphics; a graphics processing unit configured to perform processingof correcting at least one of a size of the graphics and a displayposition of the graphics, to the bitmap data of the graphics; and avideo superimposition unit configured to superimpose the bitmap data ofthe graphics to which the processing has been performed, on the videodata.

(13) A transmission device includes: a transmission unit configured totransmit a container in a predetermined format, the container includinga video stream having video data and a graphics stream having graphicsdata; and an information insertion unit configured to insert at leastone of a piece of information indicating an allowable range of sizecorrection of graphics and a piece of information indicating anallowable range of display position correction of the graphics, into alayer of the graphics stream.

A main feature of the present technology is that the processing unitthat corrects the size and display position of the subtitles (graphics)has been provided to the bitmap data of the subtitles (the graphics) sothat the subtitles (the graphics) can be favorably superimposed anddisplayed on the video (refer to FIG. 18).

REFERENCE SINGS LIST

-   -   10 Transmission and reception system    -   100 Transmission device    -   101 Control unit    -   102 Camera    -   103 Video optic-electric conversion unit    -   104 RGB/YCbCr conversion unit    -   105 Video encoder    -   106 Subtitle generation unit    -   107 Text format conversion unit    -   108 Subtitle encoder    -   109 System encoder    -   110 Transmission unit    -   111 Bitmap data generation unit    -   113 Subtitle encoder    -   200 Reception device    -   201 Control unit    -   202 Reception unit    -   203 System decoder    -   204 Video decoder    -   206 Subtitle decoder    -   207 Font expansion unit    -   208 RGB/YCbCr conversion unit    -   209 Subtitle decoder    -   209 YCbCr/RGB conversion unit    -   210, 211 Size/position conversion unit    -   212 Video superimposition unit    -   213 YCbCr/RGB conversion unit    -   214 Electric-optic conversion unit    -   215 Display mapping unit    -   216 CE monitor    -   231 User operation unit    -   232 Image sensor

1. A reception device comprising: a receiver configured to receive acontainer in a predetermined format, the container including a videostream having video data and a subtitle stream having subtitle data; andprocessing circuitry configured to control video decode processing ofdecoding the video stream to acquire the video data, subtitle decodeprocessing of decoding the subtitle stream to acquire bitmap data ofsubtitles, subtitle processing of performing processing of correcting atleast one of a size of the subtitles and a display position of thesubtitles to the bitmap data of the subtitles, and video superimpositionprocessing of superimposing the bitmap data of the subtitles to whichthe processing has been performed, on the video data.
 2. The receptiondevice according to claim 1, wherein, in the subtitle processing, the atleast one of the size of the subtitles and the display position of thesubtitles is automatically corrected on the basis of viewing positioninformation and monitor size information.
 3. The reception deviceaccording to claim 2, wherein the processing circuitry is furtherconfigured to acquire the viewing position information.
 4. The receptiondevice according to claim 2, wherein, in the subtitle processing, thefollowing expression is calculated: R=D/(M_h*f), the D representing aviewing distance, the M_h representing a height of a monitor, the frepresenting a value dependent on resolution of a video, to performscale-down correction to the size of the subtitles when the R is smallerthan a first threshold value, and to perform scale-up correction to thesize of the subtitles when the R is larger than a second threshold valuelarger than the first threshold value.
 5. The reception device accordingto claim 2, wherein, in the subtitle processing, when a viewinghorizontal position is present outer than an end point of a region in ahorizontal direction, the region being an area on which the subtitlesare displayed, a position of the region is moved to the viewinghorizontal position in the horizontal direction in accordance with adistance from the end point to the viewing horizontal position, toautomatically correct the display position of the subtitles.
 6. Thereception device according to claim 2, wherein, in the subtitleprocessing, when a viewing vertical position is present outer than anend point of a region in a vertical direction, the region being an areaon which the subtitles are displayed, a position of the region is movedto the viewing vertical position in the vertical direction in accordancewith a distance from the end point to the viewing vertical position, toautomatically correct the display position of the subtitles.
 7. Thereception device according to claim 1, wherein, in the subtitleprocessing, the at least one of the size of the subtitles and thedisplay position of the subtitles is corrected on the basis of a useroperation.
 8. The reception device according to claim 1, wherein, in thesubtitle processing, the at least one of the correction of the size ofthe subtitles and the correction of the display position of thesubtitles is limited within an allowable range.
 9. The reception deviceaccording to claim 8, wherein the processing circuitry is furtherconfigured to extract allowable range information on the correction froma layer of the subtitle stream, the allowable range information on thecorrection being inserted into the layer of the subtitle stream,wherein, in the subtitle processing, the correction is limited withinthe allowable range on the basis of the allowable range information onthe correction that has been extracted.
 10. A reception methodcomprising: receiving a container in a predetermined format by areceiver, the container including a video stream having video data and asubtitle stream having subtitle data; performing decode processing tothe video stream to acquire the video data; performing decode processingto the subtitle stream to acquire bitmap data of subtitles; performingprocessing of correcting at least one of a size of the subtitles and adisplay position of the subtitles, to the bitmap data of the subtitles;and superimposing the bitmap data of the subtitles to which theprocessing has been performed, on the video data.
 11. A transmissiondevice comprising: a transmitter configured to transmit a container in apredetermined format, the container including a video stream havingvideo data and a subtitle stream having subtitle data; and processingcircuitry configured to insert at least one of a piece of informationindicating an allowable range of size correction of subtitles and apiece of information indicating an allowable range of display positioncorrection of the subtitles, into a layer of the subtitle stream.
 12. Atransmission method comprising: transmitting a container in apredetermined format by a transmitter, the container including a videostream having video data and a subtitle stream having subtitle data; andinserting at least one of a piece of information indicating an allowablerange of size correction of the subtitles and a piece of informationindicating an allowable range of display position correction of thesubtitles, into a layer of the subtitle stream. 13-14. (canceled)